The real reason is that fingerprint.com's selling point is tracking over longer periods (months, their website claims), and this doesn't help them with that.

it allows you to track a browser forever because it is stable fingerprint point. This helps with long term tracking a great deal.

If I understand correctly, it was only stable until you restarted Firefox / your computer.

Ok that’s change it a bit but on the other hand I’ve had my browser open for weeks now and I only restart it when the “update” button turns red lol

correct. the ordering persists for as long as the original process continues to run